Daily Archives: January 5, 2013

THE LIFE CYCLE OF THE ATALA BUTTERFLY Eumaeus atala

I’ve been planning a post about this lovely small butterfly for some time. I posted a close-up photo of one taken last summer at ATLALA PICS (worth clicking to enlarge to see its cute curly tongue) but I wanted to find out more about them and their strikingly-coloured abdomens. This led me to the excellent butterfly (& co) website of STEPHANIE SANCHEZ. Click her name to be transported to her intriguingly and Greekly named HEURISTRON pages for a wealth of Florida-based lepidoptera information. With Steph’s kind approval, the following post is based on her Atala work, and includes her amazing images of the life cycle of the Atala with captions. The blue links below will take you to the relevant pages of Steph’s site, where you will find plenty of advice about Atala-friendly plants.

LARVAE Red caterpillars with yellow markings, hatch from the eggs and eat the host plant. They shed their skin several times while they’re growing up. (You can look up “larval instar” if you want to get more technical than that.)

CHRYSALIS The caterpillars eat, and grow, and then they hang from the bottom of a leaf on the Coontie, shed their skin one last time, and turn into a chrysalis.

BUTTERFLY Inside the chrysalis, the caterpillar turns into the butterfly. When it’s done, it crawls out and hangs upside-down to extend and dry its wings before it flies away.

When the caterpillars have eaten and grown enough, they hang under the leaf, shed their skin a final time, and turn into a chrysalis. The one below is undergoing the change; you can see how different it looks from the bright red caterpillars

On a very new chrysalis the yellow dots on the back of the caterpillar are still visible

Then as it ages, the chrysalis darkens to a more opaque soft brown that darkens more the older it gets

Finally, a day or so before the butterfly is ready to emerge, you can start to see the red abdomen through the bottom of the chrysalis

The little spiky brown splotches near the chrysalides are the shed skins of the larvae

When they first crawl out of their chrysalis, their abdomen is swollen with fluid and their wings are squished and tiny. They hang upside-down and excrete fluid, and also pump fluid into their wings to expand them

This is a good time to hold them; they can’t fly away. Be sure to let them hang upside-down though, or their wings will dry wrong and they will be unable to fly. Also watch out for the goo they poo because it can stain your clothes

WHY THE BRIGHT RED ABDOMEN?I suppose it’s obvious that this is one of nature’s warning signals. But are these insects inherently toxic, or are the toxins acquired by ingestion or some other process? Lifting wholesale from Wiki, which puts it as well as I could (+ useful links),“The host plants contains toxic chemicals, known as cycasins, and the bright coloration of the adult is believed to be aposematic. Birds and lizards attempt to prey on the adults, but find them distasteful and learn to avoid the brightly patterned butterflies.”

Steph advises “if you want Atala Butterflies in your butterfly garden, you’ll need at least a dozen Coontie plants to keep a colony alive; more is better. They tend to stay close to home, so they’re a fun butterfly to garden for because you can continue to enjoy watching them in your garden after they become butterflies. Some other butterflies tend to emerge and fly off.”